Personally I don't care much for the bob. The fact that he's always standing still and always facing the same direction makes training with him less realistic in a lot of ways than just hitting a heavy bag. Now I can see the bob being useful if you have some issues with targeting, and I prefer hitting a bob over a wavemaster, but I don't think I would waste the money on one unless I for some reason couldn't make it to the gym and had no way of hanging a bag.

i have tried kicking one............and it hurts even more(even when wearing a shoes)
i only use front kick,back kick,side kick(or any kick that does not use instep) and some punches when training with the dummy(no,not dummy plug).and i also aim for the face and the neck